Way back in high school, I took a very basic film class that was really informative. One of the biggest lessons it taught me was:

Directors influence films much, much more than the actors, and are usually much more consistent.

I think a lot of people think they really dislike (or like) certain actors, then they're shocked when they see them in a really good (or bad) performance. What is actually happening, though, is that the actor is appearing in a film with a much better (or worse) director.

Ever since that class, I have based my expectations of movies on their directors, and I'm surprised a lot less often.

Edit: I wrote the comment, then scrolled down to see everybody's choices. I noticed that ~90% of the actors mentioned were mostly "pretty faces" in cheesy popcorn flicks until they finally got a role in a well-directed film. I encourage you all to look up the directors of your "opinion-changing" films and see what else they've done.

Quick trivia: Speilberg didn't want to direct it originally, but only wanted to produce it. He also wanted to get Hanks and DiCaprio in the movie, but at the time they were both unavailable. Eventually, the original director dropped out. By the time Speilberg finally agreed to helm it, the actors had been freed up and joined!! Cinema gold ensued!

100% agree. I wouldn't say I hated Clooney before then but I sure didn't care for him. When I saw him play Everett it finally felt like he didn't take himself as seriously as I always assumed he did. I've enjoyed him for the most part ever since.

Easy, Heath Ledger. I hated him so much. Many are too young to remember "10 Things I Hate About You" and "A Knight's Tale". He was a "dreamy" heartthrob for teenie girls. When I heard that he was going to play the Joker in "The Dark Knight" I was highly agitated. I grumbled for weeks before I saw the movie. Rumors were that Sean Penn or even Jack Nicholson (in a reprisal) were going to have the part. I thought these serious actors would do a much better job. I thought it would ruin the franchise right after it was brought back from mediocrity. Boy have I ever been so wrong. He made that movie and even upstaged Batman himself.

I assume you think of him as "that lame asshole from Titanic." This is perfectly valid. But, as someone who first knew him as the brother in What's Eating Gilbert Grape? I gotta say he's pretty impressive when he isn't in a cheesy formulaic romance.

Sam Rockwell. I remember not liking him (I can't really remember why) until I saw Moon and realized he was incredibly talented. And Jim Carrey in The Truman Show.

Also, Tom Cruise. I still don't like him, but he has undeniable charisma onscreen. I don't want to watch him, but I still see his movies. He's one of the few modern actors I can think of who truly have "it".

I'm still not sure what to thing of him. I read an article about how he is trying to become the next big male actor, which involves him being in a thousand movies, and I just haven't seen him turn in a memorable performance yet.

But I say all this having not seen 21 Jump street, so maybe that will change my opinion of him as it did for you.

Chris Evans. I hated him in Fantastic Four, which was a shit movie, but when I saw him in Sunshine I started to appreciate him. Eventually Scott Pilgrim came out and now with him as Cap in The Avengers I consider him a pretty solid actor.

Sunshine is one of those films I actively push other people to see. It's just so damn good! I end up just calling it a psychological thriller though, rather than explaining that it's a story about nuking the sun to save the earth. lol

I think Affleck's a good actor, he just wasn't doing what he wanted to, it looked like he was getting typecast into the dreamy/troubled love interest role. Now that he's back to doing his own thing (a la Good Will Hunting) he's kicking ass again.

Marlon Wayans has still never gotten anywhere near the amount of credit he truly deserves for Don't Be A Menace. Loc-Dog is without a doubt one of the funniest, and most deranged characters ever put on film.

He actually does quite a few commercial voice-overs, none that I can think off the top of my head, but there have been numerous times where I've had a pang of vague recognition and it turned out to be J.K. Same goes for Jeff Bridges.

i always cracked me up watching him go from Oz to playing characters that are actually nice people, like his role in Juno. I guess that's good acting, getting into a character enough that you can't tell it's a role.

Justin Timberlake : Realized he could act in Alpha Dog, thought he was a boss in Social Network. Now I listen to his music too...the music I hated when it was new...crazy huh?

And the shocker:

I hated Kevin Smith. I saw clerks. I saw clerks II, Chasing Amy, Mallrats and loved ALL of them. But I was like wait this dumb motherfucker barely says anything throughout any of the movies and he's building this ridiculous resume with all of these great actors for standing there and looking dumb and stoned.

Then I realized he was the fucking producer/director and felt like a dumbass. Been in love ever since.

TL;DR : I hated Silent Bob until I found out he directed all the films he was in...world turned upside down.

This also seems crazy to me, considering how many great films he's been in. If you want action, you've got Top Gun, Mission Impossible, Minority Report and Collateral - if you want drama, Magnolia, Rain Man, Last Samurai, Eyes Wide Shut. I even dig him in movies like Valkyrie, Vanilla Sky and The Color of Money, which all get less attention. I can't think of a bad role he's done.

For a while there, Anne Hathaway seemed like a Teen Choice Award nominee and nothing more. But Rachel Getting Married showed that she's got some real talent there. Haven't really liked her in anything else though.

I hated Ryan Gosling because I just felt that he couldn't really capture the essence of.... who the fuck am I kidding. Every freaking girl out there is nuts for this guy and that's probably why I hated him.

Sean Bean. Though in hindsight I hated him because he played characters we were meant to dislike--which I guess is really just a tribute to his skills as an actor. I first saw him in Patriot Games, then Golden Eye, and as a would be agent in Ronin.

By the time I saw Equilibrium, and his tremendous role in Fellowship though, my mind was changed. : )

Keanu Reeves. First movie I saw him in was Speed then the Matrix trilogy. Stumbled upon Bill and Ted's Excellent Adventure, anyone who can be that serious of an actor while also being a complete goofball is genius, or completely crazy.

Just a note to the OP: the first movie I saw Colin Farrel in was Tigerland, and it's absolutely incredible. It shows how great of an actor he is and is actually the film that put him on the map. I always had a love for him because of it.

Hugh Grant in About a Boy. I hated him ever since I walked out of Four Weddings and a Funeral, and nothing he did either publicly or professionally deserved a change of opinion. My ex dragged me to see About a Boy, and even though I didn't want to, it was at the beer theater so I figured I could get drunk, anyway. From his first scene, I was amazed at how good he was. It's like a single golden pinnacle buttressed by crap.

I have two Behind the Curtain stories for that movie: 1. A lighting guy noticed that Michael Mann was spending tons of time coaching TC and seemingly ignoring Jamie Foxx. He thought it was favoritism until an AD told him "Jamie is fine. Tom has never played this type of role before." TC was really nervous about it.
2. There is a scene before the first kill where Cruise walks down an alley and a plane flies overhead, perfectly. During a practice run, this happened by pure luck and Mann was broken hearted that they weren't filming. TC smiles, makes a phone call, and 20 min later his private jet flew in a pattern for an hour to get that shot. That's badass.
SOURCE: Semi-confidential, but a good friend who is very high up in the crew credits.

Love that movie; there is one scene when his inner Kelso comes out, though... he'd asked his mother to bring something but she didn't, and he just gives her this wide-eyed look. I was half expecting him to yell "Damn, Jackie!"